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The code serves an area similar to Greater London, formerly known as the London Director Area. Some outer districts are covered by sections of adjacent codes and in some places the 020 code extends beyond the Greater London boundary. The code covers an area larger than the London post town.

[edit] Areas completely covered by 020

The City of London and the London Boroughs of Barking and Dagenham, Barnet, Brent, Camden, Ealing, Enfield, Greenwich, Hackney, Hammersmith and Fulham, Haringey, Harrow, Hounslow, Islington, Kensington and Chelsea, Kingston upon Thames, Lambeth, Lewisham, Merton, Newham, Redbridge, Richmond upon Thames, Southwark, Sutton, Tower Hamlets, Waltham Forest, Wandsworth and the City of Westminster are more or less completely covered by the code.

Source:http://en.wikipedia.org/wiki/020

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